Microsoft's Professional Developers Conference is currently under way, and as usual, the technical fellows at Microsoft gave speeches about the deep architecture of Windows - in this case, Windows 7 of course. As it turns out, quite some seriously impressive changes have been made to the very core of Windows - all without breaking a single application. Thanks to BetaNews for summarising this technical talk so well.

"While spinlocks comprised 15% of CPU time on systems with about 16 cores, that number rose terribly, especially with SQL Server. "As you went to 128 processors, SQL Server itself had an 88% PFN lock contention rate. Meaning, nearly one out of every two times it tried to get a lock, it had to spin to wait for it...which is pretty high, and would only get worse as time went on."

So this global lock, too, is gone in Windows 7, replaced with a more complex, fine-grained system where each page is given its own lock. As a result, Wang reported, 32-processor configurations running some operations in SQL Server and other applications, ended up running them 15 times faster on Windows Server 2008 R2 than in its WS2K8 predecessor -- all by means of a new lock methodology that is binary-compatible with the old system. The applications' code does not have to change."

Yes, Ryan, I think it'd be nice to address such scalability issues in the Haiku kernel, but.... not worry about them for R1, because that's too sensitive of an area to mutate in such a major way without a rather high risk.